The purpose of this proposal is to demonstrate the effectiveness of using ceramic coatings on plastic high-voltage insulators to increase their surface breakdown voltage and improve their recovery after a breakdown event. The goal is to produce a coating that can be applied to high-power microwave tube, coaxial plasma gun and z-pinch insulators that will allow higher voltage operation, reduce flashover events, and minimize the effects due to flashover, thereby reducing operating costs and increasing uptime.